Some of the most challenging aspects associated with producing reliable sensors suitable for use in harsh, high temperature environments include providing appropriate packaging for housing the sensing element, and selecting materials for the electrical interconnections among the sensing element and the selected package.
Various approaches have been proposed for packaging piezoresistive pressure sensors, including the utilization of a leadless semiconductor sensor chip having contacts disposed on the surface of the chip, and configured to accept pins for electrical communication, as described in U.S. Pat. No. 5,955,771 to Kurtz, et al., and assigned to Kulite Semiconductor Products, Inc., the Assignee of this Application, the contents of which are incorporated herein by reference. The leadless sensor chip approach relies on achieving excellent thermal expansion match of all of the components used, while making electrical interconnections using conductive glass/metal mixture.
As sensing elements are needed for use in even more extreme environments, including higher-pressure and/or higher temperature applications, there is a need for specific sensor designs with associated packaging and interconnections, such as described in U.S. Pat. No. 5,614,678 to Kurtz, et al., and assigned to Kulite Semiconductor Products, Inc., the Assignee of this Application, the contents of which are incorporated herein by reference.
The leadless sensor approach may be appropriate in certain sensing applications; however it would be beneficial to utilize mature wire bonding technology for metallic interconnections. Wire bonding technology has long been considered inadequate for high temperature sensor use due to reliability issues when exposed to high temperature in corrosive and/or oxidizing media.
A need exists for systems and methods in which a transducer chip can be secured within a housing and electrically connected using wire bonding, with the associated interconnections capable of reliable operation at elevated temperatures and/or extreme environments.